BOGOTA (Reuters) – Colombia has arrested 27 people accused of belonging to four smuggling networks which recruited youths to swallow drug trafficking cash profits and bring them into the South American country from Mexico, the police said on Thursday.

The money was wrapped in capsules made from latex gloves and consisted of funds from unidentified Mexican cartels. The cash was in exchange for cocaine sent by Colombian crime gangs, National Liberation Army (ELN) rebels and dissidents from the Revolutionary Armed Forces of Colombia (FARC), which demobilized last year.

The smuggling networks were broken up with help from the U.S. Immigration and Customs Enforcement agency, the police said.

The networks would recruit unemployed and poor young people to travel to Mexico and then ingest between 80 and 120 capsules of money before returning to Colombia, said General Jorge Hernando Nieto, the head of the national police.

“With each ingestion they could bring in up to $40,000, there’s even a case where they brought in $75,000 in one traveler,” Nieto told journalists. “The confiscated money in this investigation reaches $11 million.”

One of those captured had traveled between Colombia and Mexico 250 times since 2015, he said.

Colombia is the world’s top producer of cocaine, the majority of which is sent to Mexican cartels, which largely control its distribution. Colombia’s cocaine output is around 1,000 tons annually, according to security sources.